A little more than nine minutes remained in the third quarter of the Nets’ blowout of the Knicks Friday night when Mark Jackson got in Jason Collins’ face and tried to intimidate the Nets’ rookie center with a rasher of trash talk.

When the Nets drafted Collins out of Stanford, he came with a reputation of being a soft player for a big man (7-0, 260).

Instead of retreating from the veteran Jackson, Collins chatted right back at him en route up the court, forcing Kurt Thomas to come to Jackson’s defense and get into Collins’ face.

Thomas was hit with a technical and, shortly afterward, the Knicks’ last true chance to get back into game was ruined as the Nets pulled away for good.

Why is this significant?

Because with Nets’ starting center Todd MacCulloch out until at least March 5 with plantar fasciitis (inflammation of the arch) in his left foot, the position seems to be in capable hands with Collins, who’s starting in his place and will be on the Meadowlands Arena floor at the start of today’s game against the Hornets.

That alone is an upset considering how slowly Collins began his NBA career, looking way out of shape and lost in July’s rookie summer league.

After yesterday’s practice, Nets coach Byron Scott conceded that he would have “laughed at you” had anyone suggested that Collins would start a single game this season, let alone contribute important minutes as a reserve.

“I thought this kid was a year-and-a-half to two years away from giving us good minutes,” Scott said. “But when he got training camp [in October] he was a totally different player.”

Scott said in the summer league Collins, “was struggling getting up and down the floor, because he wasn’t in shape. I didn’t think he could give us 10 to 12 minutes a game.”

What caused the dramatic turnaround?

“Hard work,” Collins said yesterday. “In the summer league, I wasn’t in condition. Now, I’m in good condition . . . and we didn’t have Jason Kidd in summer league, either.”

Collins, who scored 18 points and had 12 rebounds in his first NBA start on Jan. 5 against the Hornets in Charlotte, has taken pride in doing the little things for the Nets such as diving for loose balls, taking charges and being a relentless defender and rebounder.

“I feel like that’s my role on the team,” he said. “I didn’t have to do those things in college [at Stanford, where he was a friend of Chelsea Clinton’s], where I was an inside post presence.”

Collins, whose twin brother, Jarron, is the starting center for the Utah Jazz, said he’s comfortable in his new temporary role and he promised to not stop doing the little things just because he’s being introduced with the starting five.

“He plays like he’s been in the league for awhile,” Keith Van Horn said. “It just doesn’t seem like you’re playing with a rookie. He’s a very intelligent player.”

And he’s tough, too.

“He’s not a softie,” Scott said. “That was his reputation coming into the draft and we’re still trying to figure out where that came from. He’s one of our most physical players. I loved it when he stood up to Mark and Kurt.”

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The Nets will complete a rare regular-season home-and-home when they travel to Charlotte to play the Hornets Wednesday night. . . . The Hornets, who draw no one at home because they’re set to move out of town, have won five in a row on the road.